Atrazine kills weeds and alters male rat genes.

Jul 27, 2009

Pogrmic K, S Fa, V Dakic, S Kaisarevic and R Kovacevic. Atrazine oral exposure of peripubertal male rats downregulates steroidogenesis gene expression in Leydig cells. Toxicological Sciences. Available online June 18, 2009.

Synopsis by Heather Hamlin

A widely used herbicide found in water supplies can affect rodent genes responsible for male hormone production.

The herbicide atrazine lowers the production of androgen hormones in male rats by altering the genes responsible for making them.

Although other studies have shown that atrazine can lower sex steroid hormone concentrations, this is the first study to show that atrazine directly affects the genes responsible for hormone production in testicular cells.

Atrazine is one of the two most commonly used herbicides in the US. It can run off the fields where it is applied and into surrounding water or seep through the soil to taint groundwater. Atrazine has been banned in other countries, such as the EU, due to health concerns and an inability to keep concentrations at safe levels in drinking water supplies.

Rats were fed two higher doses of atrazine, 50 and 200 micrograms per kilogram body weight. Atrazine reduced the expression of several key genes involved in the production of steroid hormones, which affects levels of the androgens important for male development and reproduction. The exposure lowered testosterone levels at the higher dose and prostate size at both doses in the male rats.